Association of serum calprotectin with clinical and laboratory manifestations of systemic lupus erythematosus (preliminary data)

Objective : to study the association of serum calprotectin (CLP) with clinical and laboratory manifestations of systemic lupus erythematosus (SLE). Material and methods . The study included 53 patients with a definite diagnosis of SLE and a median disease duration of 6 [1; 12] years; SLEDAI-2K=10 [6; 18] points. The control group consisted of 40 apparently healthy individuals matched for sex and age. Serum CLP concentration was measured by enzyme-linked immunosorbent assay using a B ü hlmann Laboratories AG (Switzerland) reagent kit according to the manufacturer’s instructions. Results and discussion . In patients with SLE, serum CLP levels were significantly higher than in the control group (3.7 [2.1; 7.4] vs 2.36 [1.77; 3.51] μg/ml; p=0.004). Patients with moderate and high SLE activity had higher CLP concentrations than those with low activity (5.61 [2.32; 8.28] vs 2.36 [1.56; 3.72] μg/ml, respectively; p=0.034). Higher CLP concentrations were associated with the presence of arthritis and elevated CRP levels, whereas lower concentrations were associated with leukopenia and neutropenia. Conclusion . In SLE, a significant increase in serum CLP is observed, which is closely associated with SLE activity, the presence of arthritis, and elevated CRP. This supports an important role of the neutrophil-mediated immunity and NETosis in SLE pathogenesis.